Bryant 345MAV D.Return Air Connections, Vi. Filter Arrangement, Ðfilter Information

D.Return Air Connections

1. Upflow Furnaces

The return-air duct must be connected to bottom, sides (left or right), or a combination of bottom and side(s) of main furnace casing as shown in Fig. 1. Bypass humidifier may be attached into unused side return air portion of the furnace casing. DO NOT connect any portion of return-air duct to back of furnace casing.

2. Downflow and Horizontal Furnaces

The return-air duct must be connected to return-air opening provided as shown in Fig. 1. DO NOT cut into casing sides or back to attach any portion of return-air duct. Bypass humidifier connec- tions should be made at ductwork or coil casing sides exterior to furnace.

VI. FILTER ARRANGEMENT

CAUTION: Never operate unit without a filter or with blower access panel removed.

Factory-supplied washable framed filters are shipped in blower compartment. Determine location for filter and relocate filter retaining wire if necessary. See Table 1 to determine correct filter size for desired filter location. Table 1 indicates filter size, location, and quantity shipped with this furnace. See Fig. 2 for location and size of bottom and side return-air openings.

TABLE 1ÐFILTER INFORMATION

FURNACE	FILTER SIZE (IN.)*			FILTER TYPE
CASING
	Side Return	Bottom Return		FRAMED
WIDTH (IN.)
17-1/2	(1) 16 X 25 X 1²	(1) 16 X 25	X 1	Cleanable
21	(1) 16 X 25 X 1	(1) 20 X 25	X 1²	Cleanable
24-1/2	(2) 16 X 25 X 1²	(1) 24 X 25	X 1	Cleanable

*Filters can be field modified by cutting frame as marked and folding to desired size. Alternate sizes can be ordered from your distributor or dealer.

² Factory-provided with furnace.

CAUTION: Air delivery above 1800 CFM requires that both sides, a combination of 1 side and bottom, or bottom only of furnace be used for return air.

NOTE: Side return-air openings can ONLY be used in UPFLOW configurations. Install filter(s) as shown in Fig. 20.

Bottom return-air opening may be used with all 4 orientations. Filter may need to be cut to fit some furnace widths. Install filter as shown in Fig. 21.

NOTE: Remove and discard bottom closure panel when bottom inlet is used.

VII. BOTTOM CLOSURE PANEL

These furnaces are shipped with bottom enclosure panel installed in bottom return-air opening. This panel MUST be in place when side return air is used.

A 3-IN. MINIMUM	COMBUSTION-AIR
	INTAKE
CLEARANCE TO
COMBUSTION-AIR INTAKE
IS REQUIRED.

ANGLE

IRON OR

EQUIVALENT

	(B)
	(A)
(B)
(A) ROD LOCATION
USING DIMPLE
LOCATORS	3/8-IN. HEX NUT	(A)
(SEE DIMENSIONAL
DWG FOR	& WASHER (4)
LOCATIONS)	REQD PER ROD	NOTES:

(A)PREFERRED ROD LOCATION

(B)ALTERNATE ROD LOCATION

VENT

3⁄8-IN. ROD

5 3⁄4″

ALTERNATE SUPPORT

LOCATION 4-IN. MIN 8-IN. MAX

DRAIN

(A)

(B)

13/16-IN. MAX

(B)ALTERNATE SUPPORT LOCATION FROM BACK

1.A 1 In. clearance minimum between top of furnace and combustible material.

2.The entire length of furnace must be supported when furnace is used in horizontal position to ensure proper drainage.

3.Bottom side combustion-air entry cannot be used when furnace is installed with hangers as shown.

A96209

Fig. 19ÐCrawlspace Horizontal Application

Ð17Ð